Robertson and Robertson.
Aims: to investigate the short term effects of deprivation by examining children in hospital. The study was done in the 1940's when children couldn't visit parents at hospital.
Procedure: Observed children in hospital, looking at how they coped with separation from their mother, the most upsetting ase was of 'John' who reacted the worst.
Findings: The main finding was that during separation, children were extremely distressed and on their return home, were less attached to their mother, being less affectionate and less happy than they had been previously.
Conclusion: All of the above effects were seen as short term and Bowlby and Robertson developed these effects into the three stages in the PDD model.
Evaluation: There were major implications for visiting hours and children were better prepared for the situation, being allowed to see their mother during her stay.